Field of the Invention
The present invention relates to a controller-integrated rotary electric machine in which a rotary electric machine and a controller for controlling the rotary electric machine are integrally configured.
Description of the Related Art
A controller-integrated rotary electric machine mounted on a vehicle, such as a car, includes a power conversion circuit for power conversion between an armature winding of the rotary electric machine and a battery provided outside the rotary electric machine. The power conversion circuit generally includes a plurality of power modules containing a semiconductor based switching device and operates as an inverter or converter under control by a gate signal applied to the gate of these switching devices.
When the rotary electric machine is caused to operate as a motor, the power conversion circuit is caused to operate as an inverter that converts DC power of the battery into AC power to be supplied to the armature winding of the rotary electric machine. On the other hand, when the rotary electric machine is caused to operate as a generator, the power conversion circuit is caused to operate as a converter that converts AC power induced in the armature winding of the rotary electric machine into DC power to be supplied to the battery.
In one controller-integrated rotary electric machine configured as above, between a power input/output terminal of the armature winding of the rotary electric machine and a power input/output terminal that is an AC-side terminal of a power module included in the power conversion circuit, and at a power input/output terminal that is a DC-side terminal of the power module, a bus bar includes one electrical coupling and at least one mechanical coupling other than the electrical coupling, and the bus bar is electrically coupled to a terminal by the one electrical coupling and mechanically coupled to a heat sink or bracket by the at least one mechanical coupling with an insulator in between (for example, see Patent Document 1).
[Patent Document 1] WO 2012/081068
However, the conventional controller-integrated rotary electric machine as described in the Patent Document 1 has a problem that since a power input/output terminal bolt is directly pressed into the bus bar, when salt water or the like penetrates from the outside to the head of the power input/output terminal bolt, the surrounding area of the press fit of the bus bar deteriorates through electrolytic corrosion, and finally, a crack occurs in the surrounding area of the press fit of the bus bar due to engine vibration and then the correct power is no longer supplied to the power module.
Furthermore, another problem is that the bus bar needs a press fit length that provides a mechanical joint surface and also, in view of the above-described problem, needs an unnecessarily large thickness of the bus bar irrespective of heat generation by electricity, leading to upsizing.